How do I weld to 14mm bolts together ?

Joined
Feb 7, 2008
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2,615
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Nottinghamshire England
Hi all

I need about 7" of 14mm bar.

I have some 14mm bolts and I want to weld two of the unthreaded portions together to get the length I need.

This will be cantilevered from an upright , however the load will be less than 40kg and only occasionally.

I need to TIG them , I wondered if there was a easy accurate way of cutting to get a better weld than a straight butt ?

Something does have to rotate on it but only a few degrees.

regards Paul
 
Joined
May 31, 2013
Messages
2,763
Location
South Benfleet, Essex, England, UK
Hi all

I need about 7" of 14mm bar.

I have some 14mm bolts and I want to weld two of the unthreaded portions together to get the length I need.

This will be cantilevered from an upright , however the load will be less than 40kg and only occasionally.

I need to TIG them , I wondered if there was a easy accurate way of cutting to get a better weld than a straight butt ?

Something does have to rotate on it but only a few degrees.

regards Paul
When I did this to produce 12mm Stainless track-rods I was advised by Sandman to do the following:
  1. Grind the ends you want to weld together into blunt/shallow "cones".
  2. Put the 2 pieces into a section of small size (12-25mm) angle-iron and clamp them in place (G-Clamps or Jubilee clips).
  3. Weld the centre joint in 3 passes going round the whole work-piece (so weld, turn,weld,turn....for each complete pass).
  4. The last pass will be putting metal on there that is fatter than the original bolts. Then use a flap-disc to smooth back down to a nice finish.
Finally, If the work is relying on the integrity of this piece.....
Put nuts over the threads to protect them and clamp it in a vise and try to break it at the joint with a hammer.

Here's one I made earlier. It is an M12 Stainless Bolt with a section of M12 Stainless LH Threading welded to the end of it instead of the bolt-head.

 
Last edited:
Joined
Oct 19, 2012
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Wakefield, UK
As Danny says. The problem is keeping the work straight and will need much clamping and unclamping as you rotate it.

 
Joined
May 31, 2013
Messages
2,763
Location
South Benfleet, Essex, England, UK
I found that I could reach 1/3rd of the circumference at a time, so I welded, let cool while firmly clamped, then rotated.... rinse-repeat for each of the 3-layers of metal deposited.
It wasn't "hard" just a pain to do.
 
Joined
Feb 7, 2008
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2,615
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Nottinghamshire England
bodged it and it seems ok.

clamped to some angle , I decided [ rightly or wrongly ] that I was having to ramp the amps up so high that it would probably be well welded for at least 3mm of depth all the way around and for 40kg occasional use that should be adequate
 
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